1. Field of the Invention
This invention relates to improved procedures for preparing CoA-SPC. Moreover, it relates to a low molecular weight substance which solubilizes the CoA-SPC contained in crude Bakers' yeast cell lysate.
2. Description of the Prior Art
Morrison et al in U.S. patent application Ser. No. 727,633, filed Sept. 29, 1976, discloses and claims a method of screening individuals for the presence of cancer. This screening test is reliable and is capable of detecting cancer at early stages of development, before any easily visible observable symptoms have appeared. Morrison et al discovered that the blood serum of individuals having cancer contained the B-protein associated with cancer. Thus, by simply analyzing blood serum for the B-protein it is possible to determine if an individual has cancer or not before any visible symptoms appear.
One detection technique disclosed by Morrison et al relies upon a reagent which comprises CoA-SPC (Coenzyme A-Synthesizing Protein Complex) Bakers' yeast extract and subtracts which interact with this extract to produce a binding protein. This binding protein is capable of binding to protein in the blood serum of humans to form a complex. The properties of this complex depend upon whether or not the B-protein is present. Thus, the use of this reagent provides a simple technique for screening individuals for cancer.
The techniques disclosed by Morrison et al for the preparation of the CoA-SPC Bakers' yeast extract produces a material containing a significant quantity of impurities, in particular, other proteins which are present in the Bakers' yeast. The purification procedures described by Morrison et al are time consuming and expensive.
The storage characteristics of CoA-SPC prepared by the prior art technique is unsatisfactory. When the CoA-SPC is lyophilized and stored, it loses a significant portion of its activity. In addition, the activity of CoA-SPC which is stored frozen at -20 decreases unacceptably with the passage of time.
Tarnowski et al is an abstract distributed at the 174th American Chemical Society Meeting held Aug. 28-Sept. 3, 1977, entitled "Preparation of the Yeast Component of the B-Protein Assay," disclosed that the CoA-SPC and other insoluble protein components of Bakers' yeast cells are solubilized by a component of the supernatant fraction. However, the CoA-SPC Bakers' yeast extract prepared by this technique contains CoA-SPC in a mixture with other proteinaceous materials.
Accordingly, a need exists for a procedure which prepares CoA-SPC Bakers' yeast extract in high purity using comparatively simple procedures.